Electro-optical device, method of manufacturing electro-optical device, and electronic apparatus

ABSTRACT

In an electro-optical device, a light-transmitting cover is disposed in mirrors, and when light is applied toward the mirrors through the light-transmitting cover, the temperature of the light-transmitting cover tires to increase due to the applied light. Here, in the electro-optical device, first metal portions that are in contact with the light-transmitting cover and the element substrate are formed. For this reason, it is possible to release the heat of the light-transmitting cover to a substrate through the first metal portions and the element substrate.

This is a divisional application of application Ser. No. 15/017,748filed Feb. 8, 2016, which claims priority to JP 2015-065935 filed Mar.27, 2015. The disclosures of the prior applications are herebyincorporated by reference herein in their entirety.

The entire disclosure of Japanese Patent Application No. 2015-065935,filed Mar. 27, 2015 is expressly incorporated by reference herein.

BACKGROUND

1. Technical Field

The present invention relates to a method of manufacturing anelectro-optical device including a mirror, an electro-optical device,and an electronic apparatus.

2. Related Art

As an electronic apparatus, there has been known, for example, aprojective display apparatus that displays an image on a screen bymodulating light emitted from a light source by a plurality of mirrors(micromirrors) of an electro-optical device called a digital mirrordevice (DMD) and then enlargedly projecting the modulated light by aprojection optical system. For example, the electro-optical device usedin the projective display apparatus includes an element substrate 1provided with mirrors 50 on one surface 1 s, spacers 28 adhering to theone surface 1 s of the element substrate 1 so as to surround the mirrors50 in planar view, and a plate-shaped light-transmitting cover 29 thatis supported by ends of the spacer 28 opposite to the element substrate1, as shown in FIG. 18. For example, the electro-optical device includesa sealing substrate 90 on which a concave-shaped substrate mountingportion 93 surrounded by a sidewall 92 is formed, and the elementsubstrate 1 is fixed to the bottom of the substrate mounting portion 93by an adhesive layer 97, and is sealed by a sealing resin 98 such as anepoxy-based material provided in the substrate mounting portion 93.

In the electro-optical device having the aforementioned configuration,light transmits through the light-transmitting cover 29, and is incidenton the mirrors 50. Light reflected from the mirrors 50 transmits throughthe light-transmitting cover 29, and is emitted. For this reason, thetemperature of the light-transmitting cover 29 is increased due to theapplied light. Since such a temperature rise leads to the temperaturerise of the electro-optical device, there is a concern that themalfunction or the life reduction of the electro-optical device occurs.

Meanwhile, as a method of increasing the thermal radiation properties ofa device mounted on a substrate, it is conceivable to provide atechnology of widening the contact area of the device and the sealingresin (see U.S. Pat. No. 7,898,724 B2). For example, as shown in FIG.18, the front surface of the sealing resin 98 is in contact with thelight-transmitting cover 29 in a position higher than a position wherethe front surface of the sealing resin 98 is in contact with thesidewall 92 of the sealing substrate 90. In such a configuration, it ispossible to increase the transmission efficiency of heat to the sealingresin 98 from the light-transmitting cover 29.

However, even though the transmission efficiency of the heat to thesealing resin 98 from the light-transmitting cover 29 is increased bythe configuration shown in FIG. 18, since the transmission efficiency ofthe sealing resin 98 is low, there is a problem that it is difficult tosufficiently suppress the temperature rise of the element substrate 1.

SUMMARY

An advantage of some aspects of the invention is to provide anelectro-optical device, a method of manufacturing an electro-opticaldevice, and an electronic apparatus which are capable of moreefficiently releasing the heat of a light-transmitting cover disposed ona side on which light is applied to mirrors.

An electro-optical device according to an aspect of the inventionincludes: a substrate; an element substrate that is mounted on thesubstrate; a mirror that is provided on a first surface of the elementsubstrate; a drive element that is provided on the first surface of theelement substrate to drive the mirrors; a light-transmitting cover thathas light transmitting properties, and is provided such that the mirroris positioned between the light-transmitting cover and the elementsubstrate; and a first metal portion that is in contact with the elementsubstrate and the light-transmitting cover.

In the aspect of the invention, a case where one member is “in contactwith” another member is not limited to a case where the members aredirectly in contact with each other, but includes a case where themembers are in contact with each other through a layer such as anadhesive layer capable of being substantially ignored in view of thermalconduction.

In the electro-optical device according to the invention, the lighttransmits through the light-transmitting cover, and is incident on themirror. Light reflected from the mirrors transmits through thelight-transmitting cover, and is emitted. For this reason, thetemperature of the light-transmitting cover tries to increase due to theapplied light. Meanwhile, in the electro-optical device according to theinvention, since the first metal portion in contact with thelight-transmitting cover and the element substrate are formed, it ispossible to more efficiently release the heat of the light-transmittingcover through the first metal portion, the element substrate and thesubstrate. Accordingly, since the temperature rise of theelectro-optical device can be suppressed, it is possible to suppress themalfunction or the life reduction of the electro-optical device.

In the aspect of the invention, it is preferable that the first metalportion is formed in a frame shape that surrounds the periphery of themirrors in planar view. In such a configuration, it is possible to moreefficiently release the heat of the light-transmitting cover through thefirst metal portion, the element substrate and the substrate.

In the aspect of the invention, it is preferable that theelectro-optical device further includes a second metal portion that isin contact with the substrate and the light-transmitting cover. In sucha configuration, it is possible to more efficiently release the heat ofthe light-transmitting cover to the substrate through the second metalportion. Accordingly, since the temperature rise of the electro-opticaldevice can be suppressed, it is possible to suppress the malfunction orthe life reduction of the electro-optical device.

The aspect of the invention may adopt a configuration in which thesecond metal portion is a metal frame that is fixed to thelight-transmitting cover and the substrate.

In the aspect of the invention, it is preferable that the second metalportion is further in contact with the first metal portion. In such aconfiguration, it is possible to release the heat to the second metalportion from the first metal portion, and it is possible to release theheat to the first metal portions from the second metal portion.

The aspect of the invention may adopt a configuration in which the firstmetal portion is in contact with an end of the light-transmitting coverclose to the element substrate and the first metal portion is in contactwith the element substrate.

The aspect of the invention may adopt a configuration in which the firstmetal portion is in contact with a lateral surface of thelight-transmitting cover and the first metal portion is in contact withthe element substrate.

The aspect of the invention may adopt a configuration in which the firstmetal portion is a metal layer that surrounds a resin portion protrudingfrom the first surface of the element substrate.

The aspect of the invention may adopt a configuration in which theelectro-optical device further includes a sealing resin that is incontact with a lateral surface of the element substrate and a lateralsurface of the light-transmitting cover between the second metal portionand the substrate. In such a configuration, it is possible to releasethe heat of the light-transmitting cover or the element substratethrough the sealing resin. It is possible to prevent moisture frominfiltrating into a portion where the mirror is provided by using thesealing resin.

The aspect of the invention may adopt a configuration in which theelectro-optical device further includes a sealing resin that is incontact with a lateral surface of the element substrate and a lateralsurface of the light-transmitting cover; and a light-transmittinginorganic material layer that is laminated on a surface of thelight-transmitting cover opposite to a surface of the light-transmittingcover facing the mirror and a surface of the sealing resin opposite to asurface of the sealing resin facing the substrate, and is in contactwith the substrate. In such a configuration, it is possible to releasethe heat of the light-transmitting cover or the element substratethrough the sealing resin and the inorganic material layer. It ispossible to prevent moisture from infiltrating by using the inorganicmaterial layer and the sealing resin.

A method of manufacturing an electro-optical device according to anaspect of the invention includes providing a light-transmitting coverhaving light transmitting properties on an element substrate thatincludes a mirror and a drive element which drives the mirrors on afirst surface, the mirror being positioned between thelight-transmitting cover and the element substrate, and thelight-transmitting cover being provided such that a first metal portionis in contact with the light-transmitting cover and the elementsubstrate; and mounting the element substrate on a substrate.

The method of manufacturing an electro-optical device according to theaspect of the invention may adopt a configuration in which the firstmetal portion is formed on the element substrate before the providing ofthe light-transmitting cover on the element substrate, and in theproviding of the light-transmitting cover on the element substrate, whenthe light-transmitting cover is provided, the light-transmitting covermay be in contact with the first metal portion.

The method of manufacturing an electro-optical device according to theaspect of the invention may adopt a configuration in which the firstmetal portion is formed on the light-transmitting cover before theproviding of the light-transmitting cover on the element substrate, andin the providing of the light-transmitting cover on the elementsubstrate, when the light-transmitting cover is provided, the elementsubstrate may be in contact with the first metal portion.

In the method of manufacturing an electro-optical device according tothe aspect of the invention, it is preferable that the method furtherincludes bringing a second metal portion into contact with thelight-transmitting cover and the substrate.

In the method of manufacturing an electro-optical device according tothe aspect of the invention, a second metal portion may be formed on thelight-transmitting cover before the providing of the light-transmittingcover on the element substrate, and in the providing of thelight-transmitting cover on the element substrate, when thelight-transmitting cover is provided, the substrate may be in contactwith the second metal portion.

In the aspect of the invention, it is preferable that when the substrateis in contact with the second metal portion, the first metal portion isin contact with the second metal portion.

The electro-optical device to which the invention is applied can be usedin various electronic apparatuses, and in this case, a light source unitthat applies light-source light to the mirror is provided in theelectronic apparatus. When a projective display apparatus is used as theelectronic apparatus, a projection optical system that projects lightmodulated by the mirror is further provided in the electronic apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like numbers reference like elements.

FIG. 1 is a schematic diagram showing an optical system of a projectivedisplay apparatus as an electronic apparatus to which the invention isapplied.

FIGS. 2A and 2B are schematic explanatory diagrams showing a basicconfiguration of an electro-optical device to which the invention isapplied.

FIGS. 3A and 3B are schematic explanatory diagrams showing an A-A′section of a major part of the electro-optical device to which theinvention is applied.

FIGS. 4A and 4B are explanatory diagrams showing an electro-opticaldevice according to Embodiment 1 of the invention.

FIGS. 5A to 5D are process sectional views showing a method ofmanufacturing the electro-optical device according to Embodiment 1 ofthe invention.

FIG. 6 is a plan view of a first wafer used in manufacturing theelectro-optical device according to Embodiment 1 of the invention.

FIGS. 7A to 7C are process sectional views showing a process of mountingan element substrate on a substrate in the method of manufacturing theelectro-optical device according to Embodiment 1 of the invention.

FIG. 8 is a sectional view of an electro-optical device according toEmbodiment 2 of the invention.

FIGS. 9A to 9D are process sectional views showing a method ofmanufacturing the electro-optical device according to Embodiment 2 ofthe invention.

FIGS. 10A to 10C are process sectional views showing a process ofmounting an element substrate on a substrate in the method ofmanufacturing the electro-optical device according to Embodiment 2 ofthe invention.

FIGS. 11A to 11D are process sectional views showing another method ofmanufacturing the electro-optical device according to Embodiment 2 ofthe invention.

FIG. 12 is a sectional view of an electro-optical device according toEmbodiment 3 of the invention.

FIGS. 13A and 13B are process sectional views showing a method ofmanufacturing the electro-optical device according to Embodiment 3 ofthe invention.

FIGS. 14A to 14C are process sectional views showing a process ofmounting an element substrate on a substrate in the electro-opticaldevice according to Embodiment 3 of the invention.

FIG. 15 is a sectional view showing another configuration example of afirst metal portion used in the electro-optical device according toEmbodiment 3 of the invention.

FIG. 16 is a sectional view of an electro-optical device according toEmbodiment 4 of the invention.

FIG. 17 is a sectional view of an electro-optical device according toEmbodiment 5 of the invention.

FIG. 18 is a sectional view of an electro-optical device according to areference example of the invention.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Embodiments of the invention will be described with reference to thedrawings. In the following description, a projective display apparatuswill be described as an electronic apparatus to which the invention isapplied. In the drawings referred to in the following description, therespective layers or the respective members are illustrated so as tohave the size capable of being recognized in the drawings, and thus,different scales are applied to each layer and each member. The numberof mirrors shown in the drawings is set such that the mirrors areillustrated so as to have the size capable of being recognized in thedrawings, but more mirrors than the number of mirrors shown in thedrawings may be provided. In the following embodiments, it is assumedthat a case where it is described that a member is “arranged close to afirst surface” may include a case where the member is arranged so as tobe in contact with the first surface, a case where the member isarranged on the first surface through another component, a case wherethe member is partially in contact with the first surface, and a casewhere the member is partially arranged through another component.

Embodiment 1 Projective Display Apparatus as Electronic Apparatus

FIG. 1 is a schematic diagram showing an optical system of a projectivedisplay apparatus as an electronic apparatus to which the invention isapplied. A projective display apparatus 1000 shown in FIG. 1 includes alight source unit 1002, an electro-optical device 100 that modulateslight emitted from the light source unit 1002 according to imageinformation, and a projection optical system 1004 that projects lightmodulated in the electro-optical device 100 as a projection image onto aprojected object 1100 such as a screen. The light source unit 1002includes a light source 1020, and a color filter 1030. The light source1020 emits white light, the color filter 1030 emits color light beamswith rotation, and the electro-optical device 100 modules incident lightat a timing synchronized with the rotation of the color filter 1030.Instead of the color filter 1030, a fluorescent substrate that convertsthe light emitted from the light source 1020 into color light beams maybe used. The light source unit 1002 and the electro-optical device 100may be provided for each color light beam.

Basic Configuration of Electro-Optical Device 100

FIGS. 2A and 2B are schematic explanatory diagrams showing a basicconfiguration of the electro-optical device 100 to which the inventionis applied, and FIGS. 2A and 2B are an explanatory diagram showing amajor part of the electro-optical device 100 and an exploded perspectiveview of the major part of the electro-optical device 100, respectively.FIGS. 3A and 3B are schematic explanatory diagrams showing an A-A′section of the major part of the electro-optical device 100 to which theinvention is applied, and FIGS. 3A and 3B are a schematic explanatorydiagram showing a state where a mirror tilts to one side and a schematicexplanatory diagram showing a state where the mirror tilts to the otherside, respectively.

As shown in FIGS. 2A to 3B, in the electro-optical device 100, aplurality of mirrors 50 is arranged close to one surface 1 s (a firstsurface) of an element substrate 1 in the form of matrix, and themirrors 50 are separated from the element substrate 1. The elementsubstrate is, for example, a silicon substrate. The mirror 50 is amicromirror having a plane size of which one side has a length of, forexample, 10 to 30 μm. The mirrors 50 are arranged in, for example, anarray of 800×600 to 1028×1024, and one mirror 50 corresponds to onepixel of an image.

The front surface of the mirror 50 is a reflection surface made of ametal reflection film such as aluminum. The electro-optical device 100includes a first layer portion 100 a that includes a substrate-side biaselectrode 11 and substrate-side address electrodes 12 and 13 formed onthe one surface 1 s of the element substrate 1, a second layer portion100 b that includes overhead address electrodes 32 and 33 and a hinge35, and a third layer portion 100 c that includes the mirrors 50. In thefirst layer portion 100 a, an address designation circuit 14 is formedon the element substrate 1. The address designation circuit 14 includesmemory cells for selectively controlling the operations of the mirrors50, word lines, and interconnections 15 such as bit lines, and includesa circuit configuration similar to a random access memory (RAM)including a CMOS circuit 16.

The second layer portion 100 b includes the overhead address electrodes32 and 33, the hinge 35, and a mirror post 51. The overhead addresselectrodes 32 and 33 are electrically conducted to the substrate-sideaddress electrodes 12 and 13 through electrode posts 321 and 331, andare supported by the substrate-side address electrodes 12 and 13. Hingearms 36 and 37 extend from both ends of the hinge 35. The hinge arms 36and 37 are electrically conducted to the substrate-side bias electrode11 through an arm post 39, and are supported by the substrate-side biaselectrode 11. The mirrors 50 are electrically conducted to the hinge 35through the mirror post 51, and are supported by the hinge 35.Accordingly, the mirrors are electrically conducted to thesubstrate-side bias electrode 11 through the mirror post 51, the hinge35, the hinge arms 36 and 37, and the arm post 39, and a bias voltage isapplied to the mirrors from the substrate-side bias electrode 11.Stoppers 361, 362, 371 and 372 that abut onto the mirrors when themirrors 50 tilt to prevent the mirrors 50 from being in contact with theoverhead address electrodes 32 and 33 are formed at leading ends of thehinge arms 36 and 37.

The overhead address electrodes 32 and 33 serve as drive elements 30that generate an electrostatic force between the mirror 50 and the driveelement 30 to drive the mirror 50 to tilt. The substrate-side addresselectrodes 12 and 13 may be configured to generate an electrostaticforce between the mirror 50 and the substrate-side address electrodes todrive the mirror 50 to tilt in some cases, and in this case, the driveelements 30 are the overhead address electrodes 32 and 33 and thesubstrate-side address electrodes 12 and 13. The hinge 35 is twistedwhen a drive voltage is applied to the overhead address electrodes 32and 33 and the mirror 50 tilts so as to draw to the overhead addresselectrode 32 or the overhead address electrode 33 as shown in FIGS. 3Aand 3B, and exerts a force for returning the mirror 50 to a postureparallel to the element substrate 1 when the applying of the drivevoltage to the overhead address electrodes 32 and 33 is stopped and anattractive force for the mirror 50 is cancelled.

For example, when the mirror 50 tilts to one overhead address electrode32 as shown in FIG. 3A, the electro-optical device 100 is in a turn-onstate in which the light emitted from the light source unit 1002 isreflected toward the projection optical system 1004 by the mirror 50. Bycontrast, when the mirror 50 tilts to the other overhead addresselectrode 33 as shown in FIG. 3B, the electro-optical device is in aturn-off state in which the light emitted from the light source unit1002 is reflected toward a light absorption device 1005 by the mirror50, and in such a turn-off state, the light is not reflected toward theprojection optical system 1004. Since such driving is performed in theplurality of mirrors 50, the light beams emitted from the light sourceunit 1002 are modulated into image light beams by the plurality ofmirrors 50 and are projected from the projection optical system 1004, sothat the image is displayed.

A plate-shaped yoke facing the substrate-side address electrodes 12 and13 is integrally formed with the hinge 35, and drives the mirror 50 byusing an electrostatic force acting between the substrate-side addresselectrodes 12 and 13 and the yoke in addition to the electrostatic forcegenerated between the overhead address electrodes 32 and 33 and themirror 50.

Entire Structure of Electro-Optical Device 100

FIGS. 4A and 4B are exemplary diagrams of the electro-optical device 100according to Embodiment 1 of the invention, and FIGS. 4A and 4 b are aplan view of the electro-optical device 100 and a sectional view takenalong line A1-A1′, respectively.

As shown in FIGS. 4A and 4B, in the electro-optical device 100 accordingto the present embodiment, the element substrate 1 in which theplurality of mirrors 50 and the plurality of drive elements 30 describedwith reference to FIGS. 2 and 3 are formed on the one surface 1 s ismounted on a mounting surface 90 s of a substrate 90 made from a ceramicsubstrate through an adhesive layer 97 made of a silver paste after theone surface 1 s is sealed by a light-transmitting cover 25.Specifically, the other surface 1 t which is a side opposite to the onesurface 1 s of the element substrate 1 adheres to the mounting surface90 s of the substrate 90 by using the adhesive layer 97. Since thesilver paste has high thermal conductivity, thermal transfer propertiesto the substrate 90 from the element substrate 1 are excellent.

A plurality of terminals 17 is formed at an end of the one surface 1 sof the element substrate 1, which does not overlap with the mirror 50 inplanar view. In the present embodiment, the terminals 17 are arranged intwo rows so as to sandwich the mirror 50. Some of the plurality ofterminals 17 are electrically connected to the overhead addresselectrodes 32 and 33 (the drive elements 30) through the addressdesignation circuit 14 or the substrate-side address electrodes 12 and13 described with reference to FIGS. 2A to 3B. Some of the plurality ofterminals 17 are electrically connected to the mirror 50 through theaddress designation circuit 14, the substrate-side bias electrode 11 andthe hinge 35 described with reference to FIGS. 2A to 3B. Some of theplurality of terminals 17 are electrically connected to a drive circuitprovided at a front stage of the address designation circuit 14described with reference to FIGS. 2A to 3B.

The terminals 17 are electrically connected to internal electrodes 94formed inside the mounting surface 90 s of the substrate 90 throughwires 99 for wire bonding. The substrate 90 is a multilayerinterconnection substrate, and the internal electrodes 94 areelectrically conducted to external electrodes 96 formed on the surface90 t opposite to the mounting surface 90 s through multilayerinterconnection portions 95 including through holes or interconnections.

Configuration of Light-Transmitting Cover 25

The light-transmitting cover 25 having light transmitting propertiesincludes a frame portion 251 (a spacer) that surrounds the periphery ofthe mirrors 50 and the drive elements (see FIGS. 2A to 3B) in planarview (for example, planar view when the element substrate 1 is viewedfrom the one surface 1 s), and a flat plate portion 252, and a portionof the light-transmitting cover 25 where the mirror 50 is disposed is aconcave portion 21. The flat plate portion 252 faces the mirror 50 on aside opposite to the element substrate 1. In other words, the flat plateportion 252 is provided such that the mirror 50 is positioned betweenthe flat plate portion 252 and the element substrate 1. In thelight-transmitting cover 25, ends 256 of the frame portion 251 close tothe element substrate 1 are fixed to the element substrate 1 throughfirst metal portion 71, to be described below. In such a state, the flatplate portion 252 faces the front surface of the mirror 50 in a positionseparated from the mirror 50 by a predetermined distance on the oppositeside of the element substrate 1.

In the present embodiment, the light-transmitting cover 25 is made froma light-transmitting member in which the frame portion 251 and the flatplate portion 252 are integrally formed. For example, thelight-transmitting cover 25 is made of light-transmitting glass in whichthe frame portion 251 and the flat plate portion 252 are integrallyformed. For this reason, the frame portion 251 and the flat plateportion 252 are continuously connected, and there is no interfacebetween the frame portion 251 and the flat plate portion 252.

In the electro-optical device 100 having the aforementionedconfiguration, after the emitted light transmits through the flat plateportion 252 and is incident on the mirror 50, the light is reflectedfrom the mirror 50, and the light transmits through the flat plateportion 252 and is output. In the present embodiment, air may be presentwithin the light-transmitting cover 25, or instead of air the inside ofthe light-transmitting cover may be filled with an inert gas, or theinside of the light-transmitting cover may be in a vacuum state.

Configuration of First Metal Portion 71

In the electro-optical device 100 of the present embodiment, the ends256 of the frame portion 251 close to the element substrate 1 are fixedto the element substrate 1 through the first metal portion 71 betweenthe terminals 17 and the mirror 50. Accordingly, the first metal portion71 is in contact with the light-transmitting cover 25 and the elementsubstrate 1. The first metal portion 71 is formed in a frame shape overthe entire circumference along the ends 256 of the frame portion 251,and surround the periphery of a region 55 where the mirrors 50 arearranged in planar view (for example, planar view when the elementsubstrate 1 is viewed from the one surface 1 s). For this reason, thefirst metal portion 71 is in contact with the element substrate 1 andthe ends 256 of the frame portion 251 over the entire circumference. Theouter periphery of the region 55 shown in FIG. 4A refers to the outerperiphery of the region where the plurality of mirrors 50 is formed, andthe mirrors 50 may not be formed in a part of the region 55.

The first metal portion 71 is, for example, metal portion formed on theelement substrate 1, and in this case, the ends 256 of the frame portion251 adhere to the first metal portion 71 through the adhesive layer. Thefirst metal portion 71 may be metal portions formed at the ends 256 ofthe frame portion 251 in some cases, and in this case, the elementsubstrate 1 adheres to the first metal portion 71 through the adhesivelayer. In the present embodiment, the first metal portion 71 is metalportions formed on the element substrate 1. For example, a silver pasteis used as the adhesive layer.

Configuration of Second Metal Portion 81

A second metal portion 81 in contact with the substrate 90 and thelight-transmitting cover 25 is formed in the electro-optical device 100of the present embodiment. In the present embodiment, the second metalportion 81 is a metal frame 85 fixed onto a surface 252 s (a frontsurface) opposite to a surface of the flat plate portion 252 of thelight-transmitting cover 25 facing the mirror 50 by an adhesive layer101. The metal frame 85 includes an end plate portion 86 facing thesubstrate 90, and a square body portion 87 protruding toward thesubstrate 90 from the outer periphery of the endplate portion 86, and anend 876 of the body portion 87 close to the substrate 90 adheres to thesubstrate 90 by an adhesive layer. Accordingly, the second metal portion81 (the metal frame 85) adheres to the substrate 90. For example, asilver paste is used as the adhesive layer. The metal frame 85 is madeof Kovar or copper.

An opening 860 is formed in a position of the end plate portion 86 whichoverlaps with the light-transmitting cover 25 in planar view. For thisreason, an end of the end plate portion 86 close to the opening 860adheres to the end of the light-transmitting cover 25 through theadhesive layer 101. Accordingly, the light-transmitting cover 25 isexposed through the opening 860 of the end plate portion 86. The endplate portion 86 is in contact with the light-transmitting cover 25through the adhesive layer 101 over the entire circumference whichsurrounds the opening 860. For example, a silver paste is used as theadhesive layer 101.

Major Effects of Present Embodiment

As described above, in the electro-optical device 100 of the presentembodiment, the light-transmitting cover 25 is disposed close to themirrors 50 to which light is applied, and when light is applied towardthe mirrors 50 through the light-transmitting cover 25, the temperatureof the light-transmitting cover 25 tries to increase due to the appliedlight. Meanwhile, in the electro-optical device 100 of the presentembodiment, the first metal portion 71 in contact with thelight-transmitting cover 25 and the element substrate 1 is provided. Forthis reason, it is possible to more efficiently release the heat of thelight-transmitting cover 25 through the first metal portion 71, theelement substrate 1 and the substrate 90. In the electro-optical device100, the second metal portion 81 in contact with the substrate 90 andthe light-transmitting cover 25 is formed. For this reason, it ispossible to more efficiently release the heat of the light-transmittingcover 25 to the substrate 90 through the second metal portion 81.Accordingly, since the temperature rise of the electro-optical device100 can be suppressed, it is possible to suppress the malfunction or thelife reduction of the electro-optical device 100.

The first metal portion 71 is in contact with the element substrate 1and the ends 256 of the frame portion 251 over the entire circumference.For this reason, it is possible to more efficiently release the heat ofthe light-transmitting cover 25 through the first metal portion 71.Since the mirrors 50 are sealed by the light-transmitting cover 25, thefirst metal portion 71 and the element substrate 1, moisture is hard toinfiltrate into a space where the mirrors 50 are arranged. Thus, whenthe mirrors 50 are driven, such a failure that the mirrors 50 areadsorbed onto surrounding members while tilting by water drops, and themirrors are not moved does not easily occur.

The second metal portion 81 is the metal frame 85 adhering to thelight-transmitting cover 25 and the substrate 90 over the entirecircumference so as to be in contact with the light-transmitting coverand the substrate. For this reason, it is possible to seal the inside ofthe metal frame 85. Accordingly, moisture is hard to infiltrate into thespace where the mirrors 50 are arranged. In the light-transmitting cover25, the frame portion 251 that surrounds the periphery of the regionwhere the mirrors 50 are arranged and the flat plate portion 252 facingthe mirrors 50 are integrally formed. For this reason, a situation inwhich moisture infiltrates through a gap between the frame portion 251and the flat plate portion 252 does not occur.

Method of Manufacturing Electro-Optical Device 100

A method of manufacturing the electro-optical device 100 according toEmbodiment 1 of the invention will be described with reference to FIGS.5A to 7C. FIGS. 5A to 5D are process sectional views showing themanufacturing the electro-optical device 100 according to Embodiment 1of the invention. FIG. 6 is a plan view of a first wafer 10 used tomanufacture the electro-optical device 100 according to Embodiment 1 ofthe invention. FIGS. 7A to 7D are process sectional views showing aprocess of mounting the element substrate 1 on the substrate 90 in themethod of manufacturing the electro-optical device 100 according toEmbodiment 1 of the invention. In FIGS. 5A to 5D, the drive elements 30are not illustrated, and a case where the number of mirrors 50 is lessthan that in FIG. 4B and two mirrors 50 are formed on one elementsubstrate 1.

As shown in FIG. 5A and FIG. 6, in order to manufacture theelectro-optical device 100 of the present embodiment, in a first waferpreparing process, a large-sized first wafer 10 is prepared. The mirrors50 and the terminals 17 are formed on one surface 10 s (a first surface)of the first wafer 10 (a silicon wafer) from which a plurality ofelement substrates 1 can be obtained for each region where the elementsubstrates 1 are divided and the drive elements 30 (see FIGS. 2A to 3B)that drive the mirror 50 are formed in the positions where the driveelements overlap with the mirrors 50 in planar view. In the presentembodiment, the first metal portion 71 including metal convex portionsis formed on the one surface 10 s of the first wafer 10 in a frame shapefor each region where the element substrates 1 are divided. For example,as shown in FIG. 5A and FIG. 6, the mirrors 50 and the terminals 17 areformed on the one surface 10 s (the first surface) of the firstlarge-sized wafer 10 (the silicon wafer) from which the plurality ofsubstrates 1 can be obtained for each region where the elementsubstrates 1 are divided, and the drive elements 30 (see FIGS. 2A to 3B)that drive the mirrors 50 in the positions where the drive elementsoverlap with the mirrors 50 in the planar view. The first metal portion71 including the metal convex portions is formed on the one surface 10 sof the first wafer 10 in the frame shape for each region where theelement substrates 1 are divided. For example, a copper paste is coatedin order to form the first metal portion 71.

As shown in FIG. 5A, in a second wafer forming process, concave portions21 are formed on one surface 20 s of a second large-sizedlight-transmitting wafer 20 (a glass wafer) from which a plurality oflight-transmitting covers 25 can be obtained for each region where thelight-transmitting cover 25 is divided. A groove 22 is formed betweenthe neighboring concave portions 21. In order to form the concaveportions 21 and the grooves 22, dry etching or wet etching using apotassium hydroxide solution is performed while a resist mask is formedon the one surface 20 s of the second wafer 20.

Subsequently, in an adhering process shown in FIG. 5B, the one surface10 s of the first wafer 10 and the one surface 20 s of the second wafer20 overlap with each other such that the concave portions 21 overlapwith the mirrors 50 in planar view (for example, planar view when thefirst wafer 10 is viewed from the one surface 10 s), and adhere to eachother using a silver paste. More specifically, the one surface 10 s ofthe first wafer 10 adheres to the first metal portion 71 formed on thesecond wafer 20 such that the concave portions 21 overlap with themirrors 50 in the planar view (for example, the first wafer 10 is viewedfrom the one surface 10 s). As a result, the first metal portion 71 isin contact with the first wafer 10 (the element substrate 1) and thesecond wafer 20 (the light-transmitting cover 25). The mirrors 50 arepositioned between the first wafer 10 (the element substrate 1) and thesecond wafer 20 (the light-transmitting cover 25) (an arrangingprocess).

Thereafter, in a dividing process shown in FIGS. 5C and 5D, unit-sizedlaminated bodies 100 s are obtained by dividing a laminated body 130 ofthe first wafer 10 and the second wafer 20 and fixing thelight-transmitting cover 25 to the element substrate 1 including themirrors 50 so as to overlap with the element substrate.

In the dividing process, the second wafer 20 is divided by allowing adicing blade (not shown) to enter the second wafer 20 until the dicingglade arrives at the grooves 22 from a side opposite to the first wafer10 in a second wafer dicing process. Subsequently, in the dividingprocess, the first wafer 10 is out by allowing a dicing blade (notshown) to enter the first wafer 10 from the second wafer 20 through cutportions of the second wafer 20 in a first wafer dicing process. As aresult, a plurality of laminated bodies 100 s in which the one surface 1s of the element surface 1 provided with the plurality of mirrors 50 issealed by the light-transmitting cover 25 is manufactured.

Next, processes shown in FIGS. 7A to 7C are performed. Initially, asshown in FIG. 7A, the element substrate 1 is fixed to the substrate 90by the adhesive layer 97 made of a silver paste (a mounting process).Subsequently, as shown in FIG. 7B, the terminals 17 of the elementsubstrate 1 and the internal electrodes 94 within the substrate 90 areelectrically connected by the wires 99 for wire bonding.

In the subsequent process, as shown in FIG. 7C, the substrate 90 iscovered with the metal frame 85 of the second metal portion 81, and theends 876 of the body portion 87 of the metal frame 85 and the substrate90 adhere to each other by the adhesive layer made of a silver paste asshown in FIGS. 4A and 4B. The periphery of the opening 860 of the endplate portion 86 of the light-transmitting cover 25 adheres to the endof the light-transmitting cover 25 by the adhesive layer 101 made of asilver paste. As a result, the electro-optical device 100 is finished bybringing the second metal portion 81 (the metal frame 85) into contactwith the substrate 90 and the light-transmitting cover 25.

Embodiment 2

FIG. 8 is a sectional view of an electro-optical device 100 according toEmbodiment 2 of the invention. FIGS. 9A to 9D are process sectionalviews showing a method of manufacturing the electro-optical device 100according to Embodiment 2 of the invention. FIGS. 10A to 10C are processsectional views showing a process of mounting an element substrate 1 ona substrate 90 in the method of manufacturing the electro-optical device100 according to Embodiment 2 of the invention. Since a basicconfiguration of the present embodiment is the same as that ofEmbodiment 1, common portions will be assigned the same referencenumerals, and thus, the description thereof will be omitted.

Similarly to Embodiment 1, as shown in FIG. 8, in the electro-opticaldevice 100 of the present embodiment, the element substrate 1 in which aplurality of mirrors 50 is formed on one surface 1 s is mounted on amounting surface 90 s of the substrate 90 made from a ceramic substratethrough an adhesive layer 97 made of a silver paste after the onesurface 1 s is sealed by a light-transmitting cover 25. In thelight-transmitting cover 25, a frame portion 251 and a flat plateportion 252 are integrally formed.

In the electro-optical device 100 having the aforementionedconfiguration, ends 256 of the frame portion 251 of thelight-transmitting cover 25 adhere to the element substrate 1. In thepresent embodiment, first metal portion 72 formed along lateral surfaces257 (in other words, the lateral surfaces 257 that connect a surface 25t of the light-transmitting cover 25 facing the element surface 1 to asurface 25 s opposite to the surface) positioned on a side of thelight-transmitting cover 25 opposite to the mirrors 50 are formedbetween terminals 17 and the frame portion 251 of the light-transmittingcover 25. The first metal portion 72 is in contact with a lateralsurface of the frame portion 251 among the lateral surface 257 of thelight-transmitting cover 25, and are contact with the one surface 1 s ofthe element substrate 1. Here, the first metal portion 72 is formed in aframe shape over the entire circumference along the lateral surfaces 257of the light-transmitting cover 25, and surround the periphery of theregion where the mirrors 50 are arranged. For this reason, the firstmetal portion 72 is in contact with the ends 256 of the frame portion251 and the lateral surfaces 257 of the light-transmitting cover 25 andthe element substrate 1 over the entire circumference.

The first metal portion 72 is, for example, metal portions formed on theelement surface 1, and in this case, an adhesive layer 102 is formedbetween the first metal portion 72 and the lateral surfaces 257 of thelight-transmitting cover 25. For example, a silver paste may be used asthe adhesive layer 102. As will be described with reference to FIGS. 11Ato 11Dd, the first metal portion 72 may be metal portions formed on thelight-transmitting cover 25 in some cases, and in this case, the elementsubstrate 1 adheres to the first metal portion 72 by an adhesive layer.In this case, when there are gaps between the first metal portion 72 andthe lateral surfaces 257 of the light-transmitting cover 25, theadhesive layer 102 is formed in the gap. In the present embodiment, thefirst metal portion 72 is metal portions formed on the element substrate1.

In the electro-optical device 100 of the present embodiment, a secondmetal portion 81 in contact with the substrate 90 and thelight-transmitting cover 25 is formed. Similarly to Embodiment 1, in thepresent embodiment, the second metal portion 81 is a metal frame 85, andends 876 of a body portion 87 close to the substrate 90 adhere to thesubstrate 90 by an adhesive layer. Accordingly, the second metal portion81 (the metal frame 85) is in contact with the substrate 90. Forexample, a silver paste may be used as the adhesive layer.

Here, the flat plate portion 252 of the light-transmitting cover 25 isfitted to the opening 860 of the end plate portion 86, and a lateralsurface of the flat plate portion 252 among the lateral surfaces 257 ofthe light-transmitting cover 25 adheres to the inner surface of theopening 860 by the adhesive layer 102 made of a silver paste.Accordingly, the second metal portion 81 (the metal frame 85) is incontact with the light-transmitting cover 25.

End 725 of the first metal portion 72 opposite to the element substrate1 adheres to the periphery of the opening 860 of the end plate portion86 through the adhesive layer 102, and the second metal portion 81 (themetal frame 85) is also in contact with the first metal portion 72.

In the electro-optical device 100 having the aforementionedconfiguration, since the first metal portion 72 in contact with thelight-transmitting cover 25 and the element substrate 1 are formed, itis possible to more efficiently release the heat of thelight-transmitting cover 25 through the first metal portion 72, theelement substrate 1 and the substrate 90. Since the second metal portion81 in contact with the substrate 90 and the light-transmitting cover 25is formed in the electro-optical device 100, it is possible to moreefficiently release the heat of the light-transmitting cover 25 to thesubstrate 90 through the second metal portion 81. Since the second metalportion 81 (the metal frame 85) is also in contact with the first metalportion 72, it is possible to release the heat to the second metalportion 81 from the first metal portion 72, and it is possible torelease the heat to the first metal portion 72 from the second metalportion 81. Accordingly, since the temperature rise of theelectro-optical device 100 can be suppressed, it is possible to suppressthe malfunction or the life reduction of the electro-optical device 100.

The mirrors 50 are sealed by the light-transmitting cover 25 and theelement substrate 1. The metal frame 85 seals the inside. In thelight-transmitting cover 25, the frame portion 251 and the flat plateportion 252 are integrally formed. For this reason, it is possible toprevent moisture from infiltrating into the space where the mirrors 50are arranged.

In order to manufacture the electro-optical device 100 having theaforementioned configuration, as shown in FIG. 9A, in a first waferpreparing process, the mirrors 50 and the terminals 17 are formed on onesurface 10 s of a first large-sized wafer 10 (the silicon wafer) fromwhich a plurality of element substrates 1 can be obtained for eachregion where the element substrates 1 are divided. In the presentembodiment, the first metal portion 72 is formed on the one surface 10 sof the first wafer 10 in the frame shape between the terminals 17 andthe mirrors 50. For example, a copper paste is coated in order to formthe first metal portion 72.

As shown in FIG. 9A, in a second wafer forming process, concave portions21 and grooves 22 are formed on one surface 20 s of a second large-sizedlight-transmitting wafer 20 (a glass wafer) from which a plurality oflight-transmitting covers 25 can be obtained.

Subsequently, in an adhering process shown in FIG. 9B, the one surface10 s of the first wafer 10 and the one surface 20 s of the second wafer20 overlap with each other and adhere to each other such that theconcave portions 21 overlap with the mirrors 50 in planar view (forexample, planar view when the first wafer 10 is viewed from the onesurface 1 s). In this case, the first metal portion 72 and the lateralsurfaces of the grooves 22 of the first wafer 10 adhere to each otherthrough the adhesive layer 102. As a result, the first metal portion 72is in contact with the first wafer 10 (the element substrate 1) and thesecond wafer 20 (the light-transmitting cover 25) (an arrangingprocess).

Thereafter, in a dividing process shown in FIGS. 9C and 9D, unit-sizedlaminated bodies 100 s are obtained by dividing a laminated body 130 ofthe first wafer 10 and the second wafer 20 and fixing thelight-transmitting cover 25 to the element substrate 1 including themirrors 50 so as to overlap with the element substrate.

Subsequently, as shown in FIG. 10A, the element substrate 1 is fixed tothe substrate 90 by an adhesive layer 97 made of a silver paste (amounting process). Thereafter, as shown in FIG. 10B, the terminals 17 ofthe element substrate 1 and internal electrodes 94 within the substrate90 are electrically connected by wires 99 for wire bonding.

In the subsequent process, as shown in FIG. 10C, the metal frame 85 ofthe second metal portion 81 covers the substrate 90, and the ends 876 ofthe body portion 87 of the metal frame 85 and the substrate 90 adhere byan adhesive layer made of a silver paste as shown in FIG. 8. The innersurface of the opening 860 of the end plate portion 86 of the metalframe 85 adheres to the lateral surfaces 257 of the light-transmittingcover 25 by the adhesive layer 102 made of a silver paste. In this case,the end plate portion 86 of the metal frame 85 and the end 725 of thefirst metal portion 72 opposite to the element substrate 1 adhere by theadhesive layer 102. Accordingly, when the substrate 90 is in contactwith the second metal portion 81, the first metal portion 72 is incontact with the second metal portion 81. As a result, theelectro-optical device 100 is finished by bringing the second metalportion 81 (the metal frame 85) into contact with the substrate 90, thelight-transmitting cover 25 and the first metal portion 72.

Another Method of Manufacturing Electro-Optical Device 100

FIGS. 11A to 11D are process sectional views showing another method ofmanufacturing the electro-optical device 100 according to Embodiment 2of the invention. Although it has been described in Embodiment 2 thatthe first metal portion 72 is formed on the first wafer 10 (the elementsubstrate 1), the first metal portion 72 may be formed on the secondwafer 20 (the light-transmitting cover 25). More specifically, as shownin FIG. 11A, in a first wafer preparing process, mirrors 50 andterminals 17 are formed on one surface 10 s of a first large-sized wafer10 (the element substrate 1) from which a plurality of elementsubstrates 1 can be obtained for each region where the elementsubstrates 1 are divided.

As shown in FIG. 11A, in a second wafer forming process, concaveportions 21 and grooves 22 are formed on one surface 20 s of a secondlarge-sized light-transmitting wafer 20 (the light-transmitting cover25) from which a light-transmitting covers 25 can be obtained. In thepresent embodiment, the first metal portion 72 is formed on the innersurface of the grooves 22 of the second wafer 20 in the frame shape. Forexample, a copper paste is coated in order to form the first metalportion 72.

Subsequently, after the one surface 10 s of the first wafer 10 and theone surface 20 s of the second wafer 20 overlap with each other andadhere to each other such that the concave portions 21 overlap with themirrors 50 in the planar view in an adhering process shown in FIG. 11B,unit-sized laminated bodies 100 s are obtained by dividing the laminatedbody 130 of the first wafer 10 and the second wafer 20 and fixing thelight-transmitting cover 25 to the element substrate 1 including themirrors 50 so as to overlap with the element substrate in a dividingprocess shown in FIG. 11C and FIG. 11D. If the processes shown in FIG.10A to 10C are equally performed in the subsequent processes, it ispossible to obtain the electro-optical device 100. However, in thepresent embodiment, the first metal portion 72 is formed close to thesecond wafer 20 (the light-transmitting cover 25), the first metalportion 72 and the element substrate 1 adhere to each other by theadhesive layer such as a silver paste in the adhering process.

Embodiment 3

FIG. 12 is a sectional view of an electro-optical device 100 accordingto Embodiment 3 of the invention. FIGS. 13A and 13B are processsectional views showing a method of manufacturing the electro-opticaldevice 100 according to Embodiment 3 of the invention. FIGS. 14A to 14Care process sectional views showing a process of mounting an elementsubstrate 1 on a substrate 90 in the electro-optical device 100according to Embodiment 3 of the invention. Since a basic configurationof the present embodiment is the same as that of Embodiment 1, commonportions will be assigned the same reference numerals, and thus, thedescription thereof will be omitted.

Similarly to Embodiment 1, as shown in FIG. 12, in the electro-opticaldevice 100 of the present embodiment, one surface 1 s of the elementsubstrate 1 in which a plurality of mirrors 50 is formed on one surface1 s is sealed by a light-transmitting cover 25. The element substrate 1is mounted on amounting surface 90 s of the substrate 90 made from aceramic substrate through an adhesive layer 97 made of a silver paste.

In the electro-optical device 100 having the aforementionedconfiguration, the light-transmitting cover 25 has a plate shape, andincludes only a flat plate portion 252. In the present embodiment, firstframe-shaped metal portion 73 is formed on one surface 1 s of theelement substrate 1 between the mirrors 50 and terminals 17 so as tosurround the periphery of a region where the mirrors 50 are provided inplanar view (for example, planar view when the element substrate 1 isviewed from the one surface 1 s). In the present embodiment, an end 735of the first metal portion 73 opposite to the element substrate 1adheres to the light-transmitting cover 25 by an adhesive layer 104 madeof a silver paste, and the first metal portions function as spacerswhich hold the light-transmitting cover 25 in positions separated fromthe element substrate 1. For this reason, the first metal portion 73 isin contact with the light-transmitting cover 25 and the elementsubstrate 1 over the entire circumference.

In the electro-optical device 100 of the present embodiment, a secondmetal portion 81 in contact with the substrate 90 and thelight-transmitting cover 25 is formed. Similarly to Embodiment 1, in thepresent embodiment, the second metal portion 81 is a metal frame 85.Ends 876 of a body portion 87 of the metal frame 85 close to thesubstrate 90 adhere to the substrate 90 through an adhesive layer.Accordingly, the metal frame 85 is in contact with the substrate 90. Forexample, a silver paste may be used as the adhesive layer.

Here, the light-transmitting cover 25 is fitted to an opening 860 of anend plate portion 86, and lateral surfaces 257 of the light-transmittingcover 25 adhere to the inner surfaces of the opening 860 by an adhesivelayer 103 made of a silver paste. Accordingly, the second metal portion81 (the metal frame 85) is in contact with the light-transmitting cover25.

End 735 of the first metal portion. 73 opposite to the element substrate1 adheres to the periphery of the opening 860 of the end plate portion86 through the adhesive layer 104, and the second metal portion 81 (themetal frame 85) is in contact with the first metal portion 73.

In the electro-optical device 100 having the aforementionedconfiguration, since the first metal portion 73 in contact with thelight-transmitting cover 25 and the element substrate 1 is formed, it ispossible to more efficiently release the heat of the light-transmittingcover 25 through the first metal portion 73, the element substrate 1 andthe substrate 90. In the electro-optical device 100, since the secondmetal portion 81 in contact with the substrate 90 and thelight-transmitting cover 25 are formed, it is possible to moreefficiently release the heat of the light-transmitting cover 25 to thesubstrate 90 through the second metal portion 81. Since the second metalportion 81 (the metal frame 85) is in contact with the first metalportion 73, it is possible to release the heat to the second metalportion 81 from the first metal portion 73, and it is possible torelease the heat to the first metal portion 73 from the second metalportion 81. Accordingly, since the temperature rise of theelectro-optical device 100 can be suppressed, it is possible to suppressthe malfunction or the life reduction of the electro-optical device 100.

The mirrors 50 are sealed by the light-transmitting cover 25, the firstmetal portion 73 and the element substrate 1. The metal frame 85 sealsthe inside. For this reason, it is possible to prevent moisture frominfiltrating into a space where the mirrors 50 are arranged.

In order to manufacture the electro-optical device 100 having theaforementioned configuration, as shown in FIG. 13A, in a first waferpreparing process, mirrors 50 and terminals 17 are formed on one surface10 s of a first large-sized wafer 10 (a silicon wafer) from which aplurality of element substrates 1 can be obtained for each region wherethe element substrates 1 are divided. In the present embodiment, firstmetal portion 73 is formed on one surface 10 s of the first wafer 10between the terminals 17 and the mirrors 50 in a frame shape. Forexample, a copper paste is formed in order to form the first metalportion 73.

Subsequently, as shown in FIG. 13B, the first wafer 10 is divided intounit-sized element substrates 1 by a dicing blade (not shown).

Thereafter, as shown in FIG. 14A, the element substrate 1 is fixed tothe substrate 90 by an adhesive layer 97 made of a silver paste.Subsequently, as shown in FIG. 14B, the terminals 17 of the elementsubstrate 1 and the inner electrodes 94 of the substrate 90 areelectrically connected by the wires 99 for wire bonding (a mountingprocess).

Subsequently, the light-transmitting cover 25 which is integrally formedwith the second metal portion 81 (the metal frame 85) covers thesubstrate 90 by the adhesive layer 103 as shown in FIG. 14C, and thesubstrate 90 and the ends 876 of the body portion 87 of the metal frame85 adhere to each other by the adhesive layer made of a silver paste asshown in FIG. 12. The light-transmitting cover 25 and the end 735 of thefirst metal portion 73 opposite to the element substrate 1 adhere toeach other by the adhesive layer 104 (an arranging process). In thiscase, the periphery of the opening 860 of the end plate portion 86 ofthe metal frame 85 and the end 735 of the first metal portion 73opposite to the element substrate 1 adheres to each other by theadhesive layer 104. Accordingly, when the substrate 90 is in contactwith the second metal portion 81, the first metal portion 73 and thesecond metal portion 81 are in contact with each other. As a result, theelectro-optical device 100 is finished by bringing the second metalportion 81 (the metal frame 85) into contact with the substrate 90, thelight-transmitting cover 25 and the first metal portion 73.

Another Configuration Example of First Metal Portion 73

FIG. 15 is a sectional view showing another configuration example of thefirst metal portion 73 used in the electro-optical device 100 accordingto Embodiment 3 of the invention. Although it has been described inEmbodiment 3 that the first metal portion 73 is formed by coating thecopper paste, the first metal portion 73 may be formed using a metallayer 732 surrounding a resin portion 731 protruding from the onesurface 1 s of the element substrate 1, as shown in FIG. 15. Such aconfiguration can be realized in such a manner that the resin portion731 is formed, the metal layer 732 is plated, and the metal layer 732 isformed.

The configuration shown in FIG. 15 is not limited to the first metalportion 73 described in Embodiment 3, but may use the first metalportions 71 and 72 described in Embodiments 1 and 2.

Embodiment 4

FIG. 16 is a sectional view of an electro-optical device 100 accordingto Embodiment 4 of the invention. Since a basic configuration of theinvention is the same as that of Embodiment 1, common portions will beassigned the same reference numerals, and thus, the description thereofwill be omitted. Similarly to Embodiment 1, in the present embodiment,as shown in FIG. 16, first metal portion 71 and a second metal portion81 (a metal frame 85) are formed. Here, the metal frame 85 is a flatplate shape, and is fixed to a sidewall 92 protruding from a bottomplate 91 of a substrate 90 by an adhesive layer. Accordingly, the secondmetal portion 81 (the metal frame 85) is in contact with the sidewall 92of the substrate 90. In the present embodiment, a sealing resin 98 isprovided between the bottom plate 91 of the substrate 90 and the metalframe 85. The sealing resin 98 surrounds the periphery of thelight-transmitting cover 25 and the element substrate 1, and is incontact with the lateral surfaces of the element substrate 1 and thelateral surfaces of the light-transmitting cover 25. Accordingly, in thepresent embodiment, it is possible to release the heat of thelight-transmitting cover 25 to the substrate 90 through the sealingresin 98, and it is possible to prevent moisture from infiltrating intoa space where the mirrors 50 are arranged by the sealing resin 98.Although it has been described in the present embodiment that thesealing resin 98 is added to Embodiment 1, the sealing resin may beadded to Embodiment 2 or 3.

Embodiment 5

FIG. 17 is a sectional view of an electro-optical device 100 accordingto Embodiment 5 of the invention. Since a basic configuration of thepresent embodiment is the same as that of Embodiment 1, common portionswill be assigned the same reference numerals, and thus, the descriptionthereof will be omitted. Similarly to Embodiment 1, as shown in FIG. 17,in the present embodiment, an element substrate 1 is mounted on asubstrate 90, and is provided with first metal portion 71. Here, asealing resin 98 in contact with the lateral surfaces of the elementsubstrate 1 and the lateral surfaces of a light-transmitting cover 25 isprovided in the inside of a sidewall 92 of the substrate 90, and alight-transmitting inorganic material layer 88 in contact with thesidewall 92 of the substrate 90 is laminated on a surface 252 s of thelight-transmitting cover 25 opposite to a surface facing the mirrors 50and a surface of the sealing resin 98 opposite to a surface facing thesubstrate 90.

Here, the light-transmitting inorganic material layer 88 is a metaloxide film such as a silicon oxide film or an ITO film, and has thermalconductivity higher than the sealing resin 98. Accordingly, it ispossible to release the heat of the light-transmitting cover 25 to thesubstrate 90 through the sealing resin 98, and it is possible to radiatethe heat through the inorganic material layer 88.

Another Embodiment

It has been described in Embodiments 1, 2, 3 and 4 that the metal frame85 is used as the second metal portion 81. However, for example, a metalfilm in contact with the sidewall 92 of the substrate 90 and the lateralsurfaces of the light-transmitting cover 25 may be laminated on asurface of the sealing resin 98 opposite to the substrate 90, and thesecond metal portion 81 may be formed using the metal film, as inEmbodiment 5.

Although it has been described in the aforementioned embodiments thatthe first metal portions 71, 72 and 73 are made of copper, the firstmetal portions may be made of aluminum. Although it has been describedin the aforementioned embodiments that the ceramic substrate is used asthe substrate 90, a substrate made of an alloy such as 42 alloy obtainedby mixing nickel with iron may be used.

Although it has been described in Embodiments 1 and 2 that the frameportion 251 and the flat plate portion 252 of the light-transmittingcover 25 are integrally formed, the invention may be applied to a casewhere the frame portion 251 and the flat plate portion 252 areseparately formed.

What is claimed is:
 1. An electro-optical device comprising: asubstrate; an element substrate that is mounted on the substrate; amirror that is provided on a first surface of the element substrate; adrive element that is provided on the first surface of the elementsubstrate to drive the mirror; a light-transmitting cover that has lighttransmitting properties, and is provided such that the mirror ispositioned between at least a part of the light-transmitting cover andthe element substrate; and a first metal portion that is in contact withthe element substrate and the light-transmitting cover, wherein thelight-transmitting cover has a frame portion and a flat plate portion,the frame portion and the flat plate portion are separately formed. 2.The electro-optical device according to claim 1, wherein the first metalportion is formed in a frame shape that surrounds the periphery of themirror in planar view.
 3. The electro-optical device according to claim1, further comprising: a second metal portion that is in contact withthe substrate and the light-transmitting cover.
 4. The electro-opticaldevice according to claim 3, wherein the second metal portion is a metalframe that is fixed to the light-transmitting cover and the substrate.5. The electro-optical device according to claim 3, wherein the secondmetal portion is further in contact with the first metal portion.
 6. Theelectro-optical device according to claim 1, wherein the first metalportion is in contact with an end of the light-transmitting cover closeto the element substrate and the first metal portion is in contact withthe element substrate.
 7. The electro-optical device according to claim1, wherein the first metal portion is in contact with a lateral surfaceof the light-transmitting cover and the first metal portion is incontact with the element substrate.
 8. The electro-optical deviceaccording to claim 4, further comprising: a sealing resin that is incontact with a lateral surface of the element substrate and a lateralsurface of the light-transmitting cover between the second metal portionand the substrate.
 9. The electro-optical device according to claim 1,further comprising: a sealing resin that is in contact with a lateralsurface of the element substrate and a lateral surface of thelight-transmitting cover; and a light-transmitting inorganic materiallayer that is laminated on a surface of the light-transmitting coveropposite to a surface of the light-transmitting cover facing the mirrorand a surface of the sealing resin opposite to a surface of the sealingresin facing the substrate, and is in contact with the substrate.
 10. Amethod of manufacturing an electro-optical device, the methodcomprising: providing a light-transmitting cover having lighttransmitting properties on an element substrate that includes a mirrorand a drive element which drives the mirror on a first surface, themirror being positioned between at lease a part of thelight-transmitting cover and the element substrate, and thelight-transmitting cover being provided such that a first metal portionis in contact with the light-transmitting cover and the elementsubstrate; and mounting the element substrate on a substrate, whereinthe light-transmitting cover has a frame portion and a flat plateportion, the frame portion and the flat plate portion are separatelyformed.
 11. The method of manufacturing the electro-optical deviceaccording to claim 10, wherein the first metal portion is formed on theelement substrate before the providing of the light-transmitting coveron the element substrate, and in the providing of the light-transmittingcover on the element substrate, when the light-transmitting cover isprovided, the light-transmitting cover is in contact with the firstmetal portion.
 12. The method of manufacturing the electro-opticaldevice according to claim 10, wherein the first metal portion is formedon the light-transmitting cover before the providing of thelight-transmitting cover on the element substrate, and in the providingof the light-transmitting cover on the element substrate, when thelight-transmitting cover is provided, the element substrate is incontact with the first metal portion.
 13. The method of manufacturingthe electro-optical device according to claim 10, further comprising:bringing a second metal portion into contact with the light-transmittingcover and the substrate.
 14. The method of manufacturing theelectro-optical device according to claim 10, wherein a second metalportion is formed on the light-transmitting cover before the providingof the light-transmitting cover on the element substrate, and in theproviding of the light-transmitting cover on the element substrate, whenthe light-transmitting cover is provided, the substrate is in contactwith the second metal portion.
 15. The method of manufacturing theelectro-optical device according to claim 13, wherein when the substrateis in contact with the second metal portion, the first metal portion isin contact with the second metal portion.
 16. An electronic apparatusincluding the electro-optical device according to claim 1, the devicecomprising: a light source unit that applies light-source light to themirror.